Kayak hull design has progressed to target specific handling characteristics that are desirable for the conditions in which it will be used. Prior to this invention there was not an easily adaptable accessory that could change the handling characteristics of a kayak hull that was designed to be very maneuverable.
Kayaks can have a variety of hull configurations that represent the keel of a traditional boat. A keel that is proud of the hull surface will have better linear tracking, than that of a boat with a smooth bottom. The vessel shown in the preferred embodiment does not have a defined keel, which is a generally longitudinal plane down the midline of the vessel, and is referred to in this writing as the virtual keel.
A vessel without a defined keel is typically very maneuverable, which also means it doesn't track in a linear manner very well. For a man powered aquatic vessel to track properly, the same amount of propelling force needs to be applied to the left side as the right side. If one side is favored, there is an amount of latent energy that will need to be released. This manifestation of energy can show itself by having the vessel turning in a direction other than its intended vector. This is wasted energy that could have been channeled in a positive direction. Technical skill and experience are required to make a smooth bottom vessel track in a linear fashion, and to minimize the loss of energy. Furthermore forces that can cause the deviation of a vessel heading include, but are not limited to wind, waves, current, primary propulsion and auxiliary propulsion.
Prior to this invention a method for changing the handling and tracking characteristics, on a vessel that tracked poorly, was to add an inboard skeg. To install a previously designed retractable skeg into an existing hull takes a fair amount of tools, special materials, and expertise. This can be accomplished by cutting an opening in the stern hull of the kayak, mounting a skeg box that has the pivot mechanism inside, then sealing the box to the raw opening. Keep in mind that once this is mounted in place, it is very difficult to re-align the rigid skeg blade with the virtual keel line. Another inherent problem is that the pivot point is below the surface of the water, which makes the hull vulnerable to leaks. The control linkage then needs to exit through the surface of the deck, and becomes a possible leak as well. A typical kayak with a retractable inboard skeg consumes some of the dry storage available, is very difficult to service while the kayak is in deep water and can be jammed by any small amount of debris, like a pebble from the beach. It can be difficult to resolve a jamming problem, since the mechanism is enclosed inside the hull, and the skeg blade is submersed.